Magic on the Hellmouth
by RegularMuggle
Summary: Xander wanted a bit of fantasy after the day he had, so he bought the silly wand from the new costume store as a little something extra. It certainly made for an interesting Halloween. Slash.
1. Chapter 1

Xander had no idea how he had ended up in this strange savannah. One moment he had been escorting kids for Halloween trick or treating and the next he had found himself here. It was very nice, long grasses, trees in the distance and a clear blue sky with hardly a cloud in sight but appearing in new places without knowing how he got there was ringing alarm bells. At least he still had his costume hat and whip, he was in proper adventuring clothes, Xander consoled himself.

He whirled around as he heard a throat clearing behind him. Shocked at the seriously out of place guy behind him. Short messy black hair, glasses, emerald eyes, and a lightning-shaped scar… oh no. That was either a very good impersonator or Harry Potter. What.

"Possession," Harry says with a friendly smile. That did and didn't explain much of what was going on right now, Harry answered without being asked "we're currently in your mind, your mind palace/scape whatever you want to call it. You dressed as me for Halloween and some mage decided to liven up the holiday and now here we are, I'm in the driving seat as it were and you're here."

"But I went as Indiana Jones" Xander protested.

"Yes, but you bought my wand, or what was described as my wand for a costume and it was the wand that was enchanted with the magic." Harry explained patiently, "The rest of your costume simply gave the spell context of 'which' Harry Potter you went as. Reality is a big place after all, easier to target a spell the more description you give it. You dressed as Indie but also had the wand tucked up your sleeve, so the spelled possessed you with someone less than 'canon' Harry Potter." Harry made a face at that last bit, "still getting used to my life, or a version of my life, being a book. Weird. Bizarre."

Xander wanted to ask how different this Harry was from the books but didn't know how to phrase it.

"The same until second year. After that, I realized that things were just going to get worse and so I got proactive about things." Xanders's eyes widened, how did he, "we're in your head and you're thinking very loudly," Harry said with a grin and gesturing to the side where a couch appeared out of nowhere.

That was some pretty impressive magic Xander decided. He had never seen Giles do something like that. "Not magic, in your head. Think of something you want and it can be made." Harry spread his arms gesturing to the whole world around them, "all of this place is you, thoughts, dreams, and emotions. It's all here and you can reshape it because it's all you, the good, the bad and the things we don't want to acknowledge. Occlumency is an amazing skill but it's not always a pleasant experience." Harry said gently from the couch and gesturing for Xander to take a seat.

Xander took the other side of the couch and decided he wanted a twinkie. The way it suddenly appeared in his hand startled him but… twinkie, so it was all of the good. Taking a bite he moaned. He couldn't remember ever having a twinkie that tasted so good.

"That's because it's a number of your memories of twinkies in one rather a singular memory," Harry explained with a teasing grin.

Xander decided that thinking quieter was something he needed to learn soonish as this was getting a little ridiculous.

"It certainly takes some getting used to" Harry replied.

Trying to change the subject from Xanders' loud thoughts and get some more information about what was going on Xander decided to ask, "so what happened when I got possessed. I was here for a time before you appeared."

"From the beginning then," Harry nods and gets comfortable.

The movement allowed Xander to see that all over Harry's clothes were tiny little squiggles. Threaded in the lining of his clothes, burnt into his belt and even now that he was looking for them Xander could see them even on his glasses.

"So I had just settled behind my bunker wards for Halloween to hopefully past me by uneventfully for once when I fall to the floor and blackout." Harry said all this dryly. Seeing Xanders confused look Harry explains ruefully, "something always happens on Halloween."

"Really? Giles told us it was too commercial for hijinks"

Harry shakes his head, "maybe in your world it is but it's been my experience that Halloween always has something happening. Perhaps, for the beings, the holiday was originally based on but these days people believe that the supernatural energies are more powerful on Halloween. All the belief lends the holiday a certain 'charge'."

Harry looks exhausted just talking about Halloween and considering their current situation happened on Halloween and what he knew of the books…

Xander decided to just move on and think about it later, "so what happened next?"

"I woke as you" Harry answered cheerfully, "well your body anyway" he clarified with a wink to a suddenly blushing Xander.

Xander had just realized that this whole mind thing wasn't just Xanders's loud thought as Harry had let out a brief spike of attraction when he spoke. "And then?" an embarrassed Xander managed to get out. This whole thing was definitely something he was going to think about when he was alone in his own head.

"Met a redhead who told me I wasn't me, she was very sure of that, that I wasn't you that is, and convinced me to save 'the slayer'? I escorted both young ladies to what Willow said was the Summers' home, we soon picked up a young lady, Cordelia. After that I secured the house with a few protective spells, you might have to deal with some vampires when this ends. I stuck them to the roof."

Harry took a breath and looked sheepish, "I'm not sure of your laws on vampires and since people were turned into their costumes I didn't know what to do with them or even if they were vampires, to begin with. You shouldn't underestimate sticking spells. After that, I decided it was high time I had a meeting with my 'host' and here we are. Willow has gone to see your Giles about fixing this, she seemed very certain that he could."

At the questioning look thrown his way Xander decided to explain a little of his backstory.

"I'll give the talk the same way Giles gave it to us," Xander explained solemnly, "To each generation, a Slayer is born, one girl in all the world, a chosen one, one born with the strength and skill to hunt the vampires."

Xander clenched his fists "a year ago my best friend was turned into a vampire, during the whole mess, Wills and me, found out about the Slayer and the whole supernatural world hiding under the normal one. That's when I knew what I wanted to do with my life. I wanted to help stop this sort of thing from happening again, so I joined up with the slayer. We've been helping ever since. We live on the Hellmouth so it seems that every other week a monster is causing trouble."

Xander looked up from his clenched fists at the comforting hand on his arm to see Harry smiling sadly at him. Remembering where they were Xander realized that Harry probably got a lot more than what was said.

Looking around for something to change the subject Xander became aware of the rapid growth of plants happening near them.

"What's happening," Xander stood in shock, he clearly remembered what they had started this conversation with. This was his mind and something changing here so rapidly couldn't be a good sign.

Harry's sigh said he knew something about it so he turned to demand answers but Harry was already answering. "That's the other reason that I wanted to have this meeting. A complex magical theory made slightly less so, all possessions leave scars depending on how deep they go."

"And what does that have to do with this," Xander gestured widely at the slow-growing oasis.

"I'm magical Xander," Harry said gently, "now I don't know how real I am. Whether I am simply a copy of this particular Harry made for this spell, it would take some serious magical power to soul-nap me across worlds, or realms or dimensions or whatever." Harry looked briefly frustrated by not being able to explain the specifics but in the next moment seemed to ignore it and power through the explanation.

"The point is that I'm real enough to be casting spells just as I remember, and since all possessions leave scars," he waved a hand at the nearly finished oasis as if that explained his point. "There's also no telling what being raised on a Hellmouth with all these energies flying around is going to do."

Xander felt understanding fill him "I have magic now?", but that was confusing, he thought to himself. Didn't Giles say anyone had the potential, what made this different? Taking a closer look at the new addition to his mind he couldn't say he was unhappy with it. It was nice, clear waters with bushes and trees surrounding it, some of them even looked like they had fruit coming into bloom.

The world shaking around him brought him out of his observation of his new magic… pool, a pond? Yes, magic pond sounded better.

Harry was already speaking quickly as he turned to him, "we don't have a whole lot of time left Xander and I still have things to say so listen carefully. Your friend Willow seems to have found the help she needed to end this and since I have no idea if I'm real or a copy or if my original will get these memories I don't know if we will see each other again."

Harry held up a hand and then formed a fist. A book appeared in front of Xander, it was old and dog eared and looked well used with a title reading Occlumency. "This is my copy of a dozen Occlumency books from beginning to intermediate, don't believe anyone who claims mastery. There is no such thing when it comes to the mind arts."

Xander clutched the book to himself like a lifeline, feeling the importance of what was being said. The shaking was worse now and everything was blurring at the edges.

"Cleansing rituals. Cleansing rituals are really important if you live somewhere magically active. You're not powerful, you'd register as a squib in the magical world but that's enough power to be tainted. Our magic is a power of the soul. We eat the various energies around us and convert it to our own personal power, however, there is only so much our souls can filter if we live in a magically powerful or corrupted area."

Harry stared hard to convey how important this was, "you live on the Hellmouth and I haven't done any research on them but from what I got from you they're bad places. Cleansing rituals" Harry repeated firmly.

The world around Xander was a blur and he couldn't make out where Harrys' voice was coming from but could still hear him.

"Oh, and Xander, Shit always happens on Halloween." Harrys' sardonic voice echoed as Xander opened his eyes to the summers living room ceiling.


	2. Chapter 2

Harry groaned in pain as he awoke. His head was throbbing and he could barely think straight.

The first thing he did was check to see if his security was compromised. If was never too much when Halloween was involved, considering the situation with the wizarding world at the moment he'd rather his security was over the top than not enough.

A quick check said his security was fine but his head was pounding inside his skull. What the hell had happened to him last night. It was always god damn Halloween wasn't it, Harry thought to himself.

Harry quickly focused himself with some occlumency, no solutions would appear without a clear head and Harry knew this well. It was with that short burst of the mind arts that he discovered what had happened to himself, or at least a clue into discovering what had happened.

New memories unfolded before his mind's eye and what strange memories they were. He doubted his soul had left his current residence, he had wards against people messing with his soul tattooed onto his back, he'd done the design work after that absolute mess with the Horcruxes and he was sure of his work.

It was far more likely that these memories had been sent by himself, the copy that had possessed Alexander Harris, or someone had implanted them.

His wards were very good, he had designed them himself and had the goblins add what they thought necessary. He very much doubted anyone had got past them to implant the memories so his current theory was that his copy had sent them.

Of course, he was right to. Harry was a very good judge of himself. They had witnessed a magical core sprout in a mindscape and since they had, technically, caused it to appear because of the possession Harry would take responsibility.

Just because Xander had a small amount of magic didn't take away the fact he had magic. Wand magic was rather restrictive when it came to power levels but there was still a great deal of magic that could be accomplished with a small amount of power. Flashy high powered spells were all well and good but sometimes all you needed was a spark to ignite a fire rather than a fireball.

Getting the most out of your magic was something not taught very well in today's magical world but using lower-powered spells and still being able to fight after your opponent had exhausted themselves was better in Harry's book. Harry thought low powered but a large effect was what was best.

Those weren't the big problems however, power levels didn't matter as much as people thought, the real problem was that having a magical core could open you up to different influences. Magical diseases, magical blood being a powerful ritual item and just the chances of your magic lashing out defensively could all be dangerous. Those were just the ones Harry could think of off the top of his head and he had no ideas of what dangers waited in Xanders world. A Hellmouth didn't sound like a pleasant place.

So yes, Harry had decided to go to this world. Not just for Xander either, no matter how handsome. New magic to explore, new knowledge and of course the adventure. If Harry didn't jump into an adventure then one was likely to find him at the worst time.

Most of his adventures started with a Halloween incident anyway, Harry thought with amusement.

Harry wouldn't be the first wizard to go travelling and certainly not the first to visit other earths either. There were crazy wizards throughout history that had done it successfully, of course, the knowledge was probably safeguarded or forgotten in the ministry somewhere.

"So, where to get answers," Harry mused aloud to himself. "Of course, where else to find restricted knowledge. The goblins."

Harry moved towards the floo and picking up a concealing cloak he was ready to go, he was already dressed for a light battle, it was Halloween after all. Harry liked to be prepared. He had business with the globins anyway.

Walking through Diagon with his hood up and a glamour spell to conceal his face just in case, Harry couldn't help but look around at the recovering shopping district. There were still boarded up shops and spell scorching along the path from previous raids even a few months after the war had ended.

The fact was that people were still frightened even with Voldemort gone. Most of his supporters, the ones that hadn't been caught red-handed at Hogwarts were still out and about. They were no longer called death eaters and had gone back to being 'respectable members of society' but people weren't as soon to forget about it this time. Twice burned and all that.

Harry continued to think about the war as he walked Diagon and continued to people watch.

The second blood war had escalated quickly but thankfully just as quickly over. He had just turned 17 this year and normally would be going into his seventh year at Hogwarts but given that more than a few people were after Harry's head, he'd given it a pass.

Voldemort had resurrected himself at that ridiculous Triwizard tournament. Which of course Harry had been involved in no matter his protests.

However, Harry had been preparing for that moment since the end of his second year. Freshly healed by phoenix tears, sitting on the dirty floor and staring at the corpse of a 60-foot basilisk Harry had come to the frightening conclusion that these end of year battles were only going to get worse.

He hadn't done anything about that conclusion over the summer, still numb from everything that had happened in the chamber of secrets. It was just a little thought that kept up at the back of his mind while gardening or making dinner for his relatives.

That changed when on the train to Hogwarts he had been attacked by a soul-sucking demon sent to Hogwarts for 'protection'. Sirius Black was apparently trying to kill him that year and the creatures he had already proven able to get past were going to be Hogwarts protection. It was that situation that made the idle thought become a need for action.

Every year in the wizarding world had become more dangerous than the last. Harry realized he needed to get in front of whatever this crazy pattern was and then wreck it. The Dursleys, despicable as they were, had taught Harry many lessons on life and being nice to your enemies was not one of them.

From third year everything Harry did was about improvement and surviving the next adventure he would inevitably end up involved with. Spells that were simple to cast and could be adapted to the situation, turtle to teapot was only a useful spell in a learning environment to build up to better things. Potions that were quick and reliable or could be thrown as a distraction, no matter how much Harry hated Snape, potions were just so damn useful.

And of course his beloved Runes. Runes could do anything as long as you knew what you were doing. Infinite adaptability, the adventurer's best friend.

Harry had managed to get out of the cemetery after Voldemort's resurrection by clever use of an animation spell cast onto the stone angel he had been tied to. It had covered him long enough to grab Cedric's body and summon the cup portkey and make it back to Hogwarts.

After that Harry had taken his preparations to the next level. More spells, more potions, the more magical theory he could take advantage of to survive the war and gathering and accounting for all the resources he had available to him and then figuring out how to leverage it.

Sirius had been fantastically supportive of him and he could never repay that. Even if Sirius had been a little… damaged, after Azkaban. He still knew how to leverage his knowledge, He still thought of everything as a prank and was just helping Harry with one but that was how he coped with everything that had been taken and done to him, and he gave Harry his unending support. Harry was glad his dogfather had left Britain after the war, somewhere sunny would do him good. Britain wasn't helping him heal.

Harry didn't have time for Umbridge and her utter stupidity during his fifth year so he had bribed the twins with his Triwizard money and told them to go wild. She had been out by Christmas and was probably planing their murder but the twins could be surprisingly vicious themselves. Harry didn't have high hopes for her attempts.

The key point that Harry had learned in that graveyard to make his goal possible was that Voldemort had called his servants, the death eaters, to him using the dark mark. Harry's mind had immediately thought of how to use that.

Harry had figured out how to tap into the dark marks connection, with a willing test subject in the form of an unfortunate death eater that had tried to kill him after fifth year during the summer.

Voldemort's attacks had increased throughout that summer and no one was doing anything to stop it. So Harry took matters into his own hands. Not legal, perhaps not even moral but something had to be done.

Harry had managed to take out half of Voldemort's support with that little experiment. Darts tipped in a paralysis potion were not to be underestimated. After that, it was dreamless sleep to his new guest and onto the next.

Sixth year had been mostly quiet which of course gave Harry time to prepare again. Every adventure and the time in between was just time to prepare for the next one. Harry was certain that there would always be a next one, he had seen the way his luck ran.

Dumbledore had wanted him to investigate how many Horcrux that Voldemort had made that year and Harry had gotten so angry he had set Dumbledoor's curtains on fire with acidental magic. "You know what a wizard can do with a single drop of someone's blood and you're saying you can't find the others when you have a piece of his SOUL right there!" Harry could still remember that conversation and it still made him annoyed thinking about it.

The war ended at the end of that year, however. Voldemort and some death eaters had infiltrated Hogwarts and were attempting to take control. Perhaps he had accelerated his plans for Hogwarts because of all the death eaters Harry had captured.

Harry had seen the attack happen on the Marauders Map when the sounds of spellfire had started and immediately went to offer his aid.

Harry had used a flash-bang and thrown a potion with vapours that would make whoever breathed them in sleep for a time. Voldemort, of course, hadn't fallen for it but in the confusion of the flash-bang, a few of his followers had.

It was still enough for Harry to get close and fire a bullet into Voldemort's head. Harry didn't discriminate when it came to survival, whatever worked is what Harry aimed to have. Getting a handgun in wizarding Britain wasn't as hard as some might think, the goblins were willing to do a lot for the right price.

So that's how the second wizarding war ending. Not a lot of magic and a muggle gun. A great many people weren't exactly pleased with Harry, having taken to capturing death eaters and holding them in an expanding trunk. Azkaban had already been attacked and no death eaters stayed by the time Harry had started his approach to the war and while people were willing to forgive his actions when he had just stopped Voldemort it still left grumbling voices.

Of course, Harry wasn't willing to just let those bastards go with a ministry apology on unlawful citizens' arrest. They would just go back to their ways if given a little time. The killings of muggles and muggle-born hadn't stopped when Voldemort died the last time and Harry had no doubt it would start back up again as soon as everyone's attention returned to their own lives.

The killings had just been done quietly when Voldemort was gone, and it would go that way again if something wasn't done. So Harry stole all their things.

Not their gold in Gringotts, Harry wasn't crazy enough to piss off the goblins and would be forever thankful that Sirius was able to gain entry to Belatrix's vault for that Horcrux, but the relics and books in their homes. He had realized after Cedric that he couldn't save everyone and everything but that didn't stop him from making some effort. If they were going to go back to their behaviour then he was going to make it slightly more difficult for them were his thoughts at the time.

Harry had gone after books, dark artifacts and any death eater caches he could find, he knew he didn't get them all but he was hopeful that it would slow them down for a time.

He had done his part and more, he just had to hope that there were still others looking out and would stop them from doing too much damage.

Harry had too much attention on him now, no-one had been able to link the thefts to him but he had been rather outspoken about his opinions on them and he had the skills to do it. So, of course, eyes had turned to him and the grumbling voices from before picked up speed.

Looking up at Gringotts Harry decided that this trip to another earth might be just what he needs. Another adventure to take, new magic to explore and some danger for spice. Sometimes Harry regretted not having a normal life but as he nods to the goblins on guard and walks into Gringotts all he can feel is his excitement.

Time to prepare, he thought with a pleased grin.


End file.
